Chuck for paper rolls



June 28, 1960 P. N. NELSON 2,942,892

CHUCK FOR PAPER ROLLS Filed May 8, 1956 2 Sheets-Sheet 1 IN V EN TOR.

Mu 7 5 W% June 28, 1960 P. N. NELSON 2,942,892

CHUCK FOR PAPER ROLLS Filed May 8, 1956 2 Sheets-Sheet 2 IN VEN TOR.

United States Patent Ofiice CHUCK FOR PAPER ROLLS Permil N. Nelson, Galesburg, 111., assignor to Lynn H. Ewing, Rock Island, 11].

Filed May 8, 1956, Ser. No. 583,506

2 Claims. (Cl. 279-2) The present invention pertains generally to expansible chucks and more specifically to expansible chucks for supporting a hollow core paper roll on a shaft.

One object of the present invention is to provide an improved expansible chuck which, when placed on a shaft and inserted in the core of a paper roll, affords a secure gripping action on both the core and the shaft resulting in a positive driving connection therebetween.

Another object of the present invention is to provide an expansible chuck having the foregoing characteristics which precisely centers the shaft within the paper roll core under all conditions of adjustment and which may be used for a wide range of core sizes.

Other objects and advantages will become apparent from the following detailed description of the invention taken. in connection with the accompanying drawings wherein:

Figure 1 is an isometric view of a paper roll mounted on a shaft by means of a pair of chucks illustrative of the present invention.

Fig. 2 is a sectional view taken substantially in the plane of line 2-2 of Fig. 1 and showing the novel chuck in detail.

Figs. 3 and 4 are sectional views taken substantially in the plane of lines 3-3'and 4-4 respectively of Fig. 2 and showing end views of the novel chuck.

Fig. 5 is an enlarged perspective view of a pair of cooperating wedge members forming a part of the novel chuck. I

While the invention is susceptible of various modifications and alternative constructions, a certain illustrative chuck has been shown in the drawings and will be described below in detail. It should be understood that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention as expressed in the appended claims.

In the paper and printing industries large paper rolls are generally formed by winding the paper on tubular cores or the like which are formed of paper, wood, or metal. These cores may be either of the expendible type which can be discarded after use or of the returnable types. Regardless of which type of core is used, it is desirable to use as much as possible of the paper which is rolled on them. Where the paper roll cores are of the expendible type of which paper cores are a good example, it is necessary to provide means for mounting these rolls on suitable shafts which shafts are in turn mounted on the particular printing or other machine. The shafts are generally mountable on such a machine by means of suitable bushings and, in many instances, are drivingly connected to the power mechanism of the machine so as to afford a positive drive for winding or unwinding the paper roll. Because these shafts are separable from the expendible cores, only a limited number are required. For this reason expendible cores are more desirable because they eliminate the necessity of storing and shipping a large number of heavy, empty cores. These shafts extend through the center of the core and it is desirable that they be centered within the roll to prevent the roll from wobbling or shaking at high rotary speeds with resultant undesirable vibrations. Further, because the rolls are heavy, they tend to coast or slip on the shaft making desirable a secure driving connection between the paper roll core and the shaft.

In accordance with the above objects, the present invention is exemplified by a pair of novel chucks indicated generally at (Fig. 1) mounted on a shaft 11 and extending into each end of a core 12 of a paper roll'13.

Briefly each chuck 10 can be expanded by external means to center the roll 13 on the shaft 11 and to grip both the shaft and the roll in such a manner as to provide a driving connection between them. The chuck is susceptible of both rapid attachment and detachment and inner leaves 16 for gripping the shaft and a plurality of Each.

outer -leaves,17 for gripping the paper roll core. inner leaf 16 is formed with a concave gripping surface 19 (Fig. 5) having a radius approximately equal to the radius of the shaft 11.

" respond in number thereto. Each of these outer leaves afforded by the separation of the leaves.

17 is formed with a convex gripping face 20 of an outer' radius approximately equal to the inner radius of the core to be used. In most circumstances the core will be deformed to, accommodate itself to the gripping face 20 which may be roughened in any suitable manner to enhance its ability to nonslidably engage the core.

In order to prevent the chuck from being inserted toofar within the core, an annular shoulder 22 is provided on each of the outer jaws for engaging the endof the paper roll core 12.

Provision is made for forcing the inner and outer leaves radially apart from each other and into gripping contact with the shaft and the roll respectively. To this end mutually inclined surfaces 24 and 25 are provided on the outer surface of the inner leaf 16 and the inner surface of the outer leaf 17 respectively. In the illustrated chuck these mutually inclined surfaces consist of a single gentle taper forming a wedge on each leaf so that relativeaxial movement between the inner and outer leaves 16 and 17' results in a relative radial movement. In this manner, the mutually inclined surfaces 24, 25 cooperate to space. the leaves from a minimum to a maximum distance apart as determined by the slope of the taper and the axial positions of the leaves. It can thus be seen that an axial force tending to move the radial force acting through the inclined surfaces 24 and 25 against the surfaces of the core and the shaft respectively. Accordingly, the inner diameter .of the core and the diameter of the shaft can be varied within the limit The chuck 1G is thus adaptable for use with various sizes of shafts and cores.

Suitable provision is made for axially moving the leaves relative to each other. One means for accomplishing this is shown, for example, in the form of an externally threaded sleeve or bushing 28 secured to the shaft 11 adjacent the chuck 10 and the end of the paper roll 13. This bushing is held in place by a suitable clamping device such as one or more set screws 29 or the like..

Pafent ed Jun e 2 8, 1960,.

Three or four of these inner] leaves 16 are disposed around the periphery of the shaft' The threaded bushing 28 shaft 11 according to the length of the paper roll which is determined by the width of the paper thereon.

Toaxially position the leaves, an internally threaded.

nut 30 is threadably engaged withthe bushing 28.and-

shoulder 31' on the inner leaves to force those leaves axially with the nut. This .axial force is transmitted to the outer leaves. 17 through the mutually inclined surfaces 24, 25 and forces them outwardly andinto engagenient with the paper roll core 13.

In order to exert a suihcient force on the nut to urge the outer leaves against the core, force applying means are provided on the nut 30. Accordingly, the nut is formed with a capstan flange 34 having suitable openings for receiving a force applying instrument 33 such as a spanner wrench or the like. The outerleaves are prevented from sliding axially within the core when an axial force is applied on the inner leaves by the annular shoulder 22 projecting outwardly from the end of each outer leaf into engagement with the end ofthe core 12;

v In order to loosen the chuck priorto removing it-from the core, means. are .provided to exert an axial force on a the 'innerleaves tending-to withdraw them from engagement with the'outerleaves. For example, a plurality of: pins 35 or the likeiare provided adjacent the end one leaf projects radially into an axially extending slot 39 on the other leaf (Pig. The leavesof the chucks are held together. as units by means of continuous coil.

springs 42 seated: in annular grooves 43 cut on the external surfaces of the inner and outer leaves.

'When'the chucksare to be used for mounting a paper roll oni a shaft, one chuck is mounted on the shaft and is held thereby the tension of the coil springs 42. The shaft-11 is then inserted into the core of the paper roll 131so-fhat the chuck it). is positioned within one end of the roll and the other chuck is slid over the free end of the shaft and into the. core of the roll. With the shoulders on the outer leaves of each chuck engaging. a the ends of. the core, the chucks are properly positioned and the set screws 29 on the threaded bushing 28 of each chuck are tightened to secure the bushing on the 'shaft. To expand the outer leaves against the tension of the coil springs into contact with the roll and contract the inner leaves into engagement with the shaft; a spanner' wrench is applied to the threadednut 30 of each chuck to forcefully rotate the same and apply an axial force on the inner. leaves. This tightening action on the chucks centers the shaft Within the roll of paper and is thus adjustable along the V of said spring upon relative axial' movement between holds it securely in driving engagement with the paper 1 roll.

The shaft mounted paper roll 13 is then placed in suitable journal'bearings and any. desired power mechanism attachedt Under the above mounting conditions, theroll of paper will not slip when it is being driven or coast due to-stored inertia because of the positive connection afforded by the novel chuck. Further, the, roll will not vibrate at high rotational speeds because the above described novel chuck centers it on the shaft.

The core and the shaft are easily disassembled by the simple expedient of rotating the nuts to loosen the leaves of both chucks, removing one chuck, and sliding the shaft carrying the other chuck out of the core of the paper roll.

The chucks are susceptible of both rapid attachment and detachment and are simply and easily installed around the shaft on which'they are to be used. 'The chuck itself is desirably formed of a light material such as aluminum, although any suitable metal or other material of suificient strength can be used; Inasmuch as the members of the chuck are in compression, the chuck is inherently strong and is suitable for use with large, heavy rolls of paper. The mutually inclined surfaces on the leaves allow a wide range of adjustment to adapt the chuck for use with various sizes of cores while maintaining the outer surface of the chuck parallel to the core and thereby insuring that the core is centered on the face for engaging the inner surface of the core, at =least one continuous coilspring surrounding said outer leaves,-

mutually'rinclined wedges onsaid outer and inner'leaves for radially separating said leaves against the tension of said spring upon relative axial movement between said inner and outer leaves, means for preventingrotati'on ofsaid outer'leaves on said inner leaves; said means comprising a, key on "at least one wedge cooperative with a key-slot 'on the mutually inclined wedge directly opposed thereto, an externally threaded bushing fixably engageable on the shaft, and an internally threaded nut on said bushing and engageable with one end of saidinner leaves to move said inner leaves axially of said outer leaves for expanding said chuck into secure gripping engagement with the paper roll and the shaft.' 7

- 2. A chuck for securing a hollow 'core paper roll on a shaft comprising, incombinati'on, a plurality of inner leaves having a concave inner surface forengaging' the shaft, a plurality of outer leaves corresponding in number to said inner'leaves and having a convex outer surface for engaging the inner surface of the core, at least one continuous coil spring surrounding said outer leaves,

mutually inclinedwedges on said-outer and-inner leaves for radially separating said leaves against the tension said inner andouter -leaves, means for; preventing rotat-ion of said outer leaves on said'inner leaves, said meanscomprising'akey on the 'we'dge of each or the inner leaves cooperative with a key-slot on the mutually inclined wedge directly opposedthereto of an outer' leaf," an externally threaded bushing fixedlyfengageableon thesha'ft, and aninternally threaded nut on said bushing and engageable with one end of said inner leaves to move said innerleaves axially of said outer leaves for expanding .said chuck into secure gripping engagement with the paper roll and the shaftgsaid key and key-slut being longitudinally medially disposed on the wedges of said" inner and outer leaves. I p 7 V a V I References Cited in the file of this patent V 7 V FOREIGN PATENTS" W 120,134. Great Britian Oct. 3 1, i918 

